1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor light emitting device, and more particularly, to a method for manufacturing a semiconductor light emitting device, which is capable of providing high characteristic homogeneity and reproducibility.
2. Discussion of the Related Art
By virtue of the recent technical advance, a celadon green semiconductor laser has been commercially available. Currently, the celadon green semiconductor laser is used as a light source for high-density information recording appliances such as HD-DVD and Blue-ray Disk systems, display appliances, illumination appliances, etc.
However, the market of the celadon green semiconductor laser is still restricted due to the insufficient power, short life span, and high price of the celadon green semiconductor laser. To this end, it is necessary to develop a technique capable of inexpensively manufacturing a device having an increased optical power and a high reliability.
Recently, a technique capable of fabricating a single-crystalline GaN-based substrate having a large area has been developed. This technique uses a method of growing a thick film over a sapphire or GaAs substrate in an unbalanced state, using a vapor deposition process, and then removing the substrate used as a mother body.
In the case of the single-crystalline GaN-based substrate fabricated in accordance with the vapor deposition method, however, it is difficult to stably secure a desired homogeneity because the single-crystalline GaN-based substrate is fabricated by growing a thick GaN crystalline film over a mother substrate such as a sapphire substrate, different from a Si single-crystalline substrate obtained by cutting a large ingot. Furthermore, the thick GaN film may be subjected to stress due to the thermal expansion coefficient difference between the GaN film and the mother substrate. As a result, the GaN film may be bent or may have much crystal defect.
In addition, there is a problem or limitation in reducing the manufacturing costs because a complex post process is required to remove the mother substrate. For this reason, a single-crystalline GaN substrate having a high quality is expensive, and has a limitation on the supply amount thereof.
As a result, where a semiconductor device is fabricated on the above-mentioned single-crystalline GaN-based substrate, which is inhomogeneous, there is a problem in that the characteristics and reproducibility of the semiconductor device are greatly influenced by the conditions of the substrate, so that the yield of good-quality products may be degraded.
Under the above-mentioned circumstance, it is required to provide a technique capable of inexpensively producing a homogeneous single-crystal GaN-based substrate having a high quality or a technique capable of reproducibly fabricating devices, using the same GaN-based substrate, as the substrate is again used, after the fabrication of one device, to fabricate another device.